Global offset
The global offset shifts the timecode address that LTCast displays and broadcasts, relative to the position encoded in the audio file. Use it when your LTC audio starts at a specific SMPTE address and you need to fine-tune the alignment.
What the offset does
When LTCast decodes LTC from an audio file, it reads the timecode address directly from the signal. The global offset adds or subtracts a fixed number of frames from that decoded address before displaying it and before sending it on MTC, Art-Net and OSC.
A positive offset moves the displayed timecode forward (later). A negative offset moves it backward (earlier). The offset is measured in frames at the current frame rate.
Example: if the LTC in your audio file starts at 01:00:00:00 and your show clock is supposed to start at 01:00:00:10, set the offset to +10.
Where to find the offset control
In the transport row, to the left of the play buttons, a collapsed Offset summary shows the current value (for example +10f). Click it to expand the controls: − and + buttons, a slider and a number box, from −999 to +999 frames. Double-click or right-click the slider to reset it to 0.
You can also nudge the offset with the mouse wheel over the offset controls or over the large timecode digits: one frame per notch, or ten frames with Shift held. The wheel nudge on the digits is switched off while the interface is locked.
Keyboard nudge shortcuts
Shift+,— nudge offset backward by half a beatShift+.— nudge offset forward by half a beatCtrl+,— nudge offset backward by one beatCtrl+.— nudge offset forward by one beat
The beat size is calculated from the current BPM, which comes from tap tempo or from detection. These shortcuts need a loaded song and a known BPM — without one they do nothing. If the active song has its own Song offset, the shortcuts change that song's offset instead of the global one.
Global vs per-song offset
The global offset applies to the entire session. Each song in the setlist can also carry its own Song offset value, set in frames from the arrow on the song's row (see Song offset). When a song has a per-song offset, that value overrides the global offset for that song only. Songs with no per-song offset use the global value.
A song's own offset is read when the song is loaded. If you edit the offset of the song that is already loaded, the change takes effect the next time it loads; changing the global offset during a song replaces the offset in use straight away, until the song is loaded again.
- Global offset — applies when there is no per-song override; useful for a show where all songs share the same start address convention
- Per-song offset — overrides the global value for individual songs; useful when different songs have different embedded start addresses
Resetting the offset
Type 0 in the offset number box, or double-click (or right-click) the slider, to reset the global offset to zero. The timecode display immediately reflects the change.